Letters to the Editor
5151 E. Memorial Dr., Muncie IN 47302
USC Errata
There were typos in the "Universal Slow Charger" article in the September 2000 MA:
- In the Circuit Card Assembly drawing, page 42, the designation "C2" appears twice. The correct C2 is the 0.01 µF capacitor. The 47 µF 16-volt capacitor should be labeled "C4."
- In the same drawing, "C4 4.7 µF 100V" capacitor should be labeled "C5 4.7 µF 100V."
- In the same drawing, "D2 1N4002" is correct, but it appears as "1N4004" in the Parts List, page 46. Either part number is okay.
- Parts List, Control Circuit, page 46: C5 catalog number is given as 900-1729. This should be 900-1719.
- Parts List, Advanced Power Supply, page 46: R6 is not listed. It should be 47K, catalog number 900-0258.
- The 9xx- catalog numbers are parts from Radioshack.com—the commercial partner of your local Radio Shack store. If you are not online, these parts can be ordered at (800) 442-7221, or through your local Radio Shack retail store. They are not stocked at the latter, but sometimes equivalents can often be found under store 2xx- numbers such as R6 (271-1342) in item 5 above.
I apologize for any inconvenience this has caused.
Bob Konspi Lansdale, Pennsylvania
Radio Eyes
Just wanted to comment that I thought the article in the September 2000 issue by Rick Allison was excellent. He took a difficult and confusing subject and made it make sense in a well-organized and effective manner. I was most impressed with his thoroughness and attention to detail.
Modelers depend so much on efficient vision in all facets of the hobby—not only to fly well, but also from the viewpoint of safety. I was glad that he emphasized the importance of sunglasses and the need to have periodic eye exams.
I'm both an ophthalmologist and an optometrist, as well as a former military flight surgeon, and was very pleased to see this topic covered so well.
H. Jay Bruning, M.D. Jacksonville, Illinois
Rick Allison's article "Radio Eyes" in the September issue of Model Aviation contains very misleading statements concerning the best health care provider to go to for an eye exam. Rick incorrectly states that optometrists are only licensed to examine for visual problems and prescribe glasses, whereas an ophthalmologist can also treat eye disease.
Optometrists are primary care practitioners, much like family practice physicians in the medical community. They serve as the gatekeepers of eye care, taking care of the majority of a patient's vision health needs, and referring patients to the appropriate specialist (ophthalmologist, neurologist, internist, etc.) if further care is required. Rick's statements are actually more descriptive of an optician, who can often dispense glasses but not medications.
Confusion over the duties of the three "O's" of eye care is widespread, so I hope my letter provides some insight.
Stanley J. Sadorf, O.D. Victorville, California
Mr. Rick Allison's article "Radio Eyes" was a fantastic article. When it came to explaining the visual system, he did a great job for the nonmedical fliers. The pictorials were also very good.
Some points made that were totally wrong were about the relationship of the ophthalmologist vs. the optometrist. He states that an ophthalmologist is the only doctor to treat eye disease as well as assess overall eye health. I'm an optometrist, and I can do anything an ophthalmologist can do, except surgery. Part of what I do, as well as other optometrists, is to thoroughly assess eye health during every eye examination. My training, eight years total, has given me the ability to examine, treat, and prescribe pharmaceuticals and/or corrective lenses for the eyes.
Mr. Allison should research what different eye professionals in different states do before recommending anything to AMA readers. Some states even allow optometrists to do certain types of laser surgery.
Keep up the good work producing a great magazine.
Brian E. Kurz, O.D. Eufaula, Alabama
Selecting Slope Sailplanes
Thank you very much for the article, "Selecting Slope Sailplanes" by Dave Garwood (July issue). Although I have been flying slope since 1974, I found the article very informative. I am the Contest Director of the La Sierra Soaring Association and always appreciate the opportunity to share new information with our club members. The article mentioned many airplanes we have been flying and a few we were not familiar with. Some of our members are now going to try those models, based on the recommendations in the article.
Dave mentioned the Mad Aircraft Highlander, and the fact that he had yet to try it or see it flown. One of the youngest members, 16-year-old Keith, got the Highlander as his first trainer about three months ago. It has an SD 7037 airfoil, which makes it just a little steeper than a flat-bottom-airfoil trainer, but better for wind penetration on the slope.
It is very maneuverable, yet docile enough for the beginner when using low rates. The best feature for the beginner is that it is made of EPP (Expanded Polypropylene) foam, which is nearly indestructible. That means a beginner can concentrate on learning to fly without the fear of destroying his airplane in a crash.
We have a Web site at www.lash.homestead.com. The Contest Director's log section has model reviews, building, and flying tips. It is updated monthly and we welcome people to log on.
Charles Varvaro Norco, California
Noise
A lot of model airfields are lost because the neighbors complain about the noise.
Maybe AMA could start a crusade to get manufacturers to include the decibel rating in their advertisements. That would spark engine and muffler manufacturers to compete in developing better mufflers.
And I understand there is a method of noise reduction using sound electronically generated to partly cancel noise vibration. Maybe in this age of miniaturization, this could be a solution.
Bob Penko Euclid, Ohio
Fun With a $3 Model
A few weeks ago, I decided to build an RC glider. My Dad has one, and its graceful, soaring flights sure beat being hunched over a finicky, messy glow engine. At that time, however, I had little money. (I'm 14, and my income comes from babysitting.)
So I began looking for alternative ways to get into the air as cheaply as possible. I found the answer at a nearby store.
My two-channel hand-launched glider (a Life-Like Silver Streak) started as a kid's foam glider, for which I paid $3. I cut spaces out of the top for the receiver, servos, and NiCd (which I already had from previous aircraft). These are carefully positioned so as not to disturb the center of gravity.
The 4½-foot wingspan provides ample lift, and the adjustable elevator eliminates trim adjustments! Its flight characteristics are better than some two-meter sailplanes, and certainly better than I expected from a $3 model.
The only drawback is that the airframe is completely Styrofoam®, which breaks very easily on a hard landing.
This airplane has had many excellent flights. Yes, the elevator's location does cause some "aileron effect," but it can easily be corrected with a little rudder. Although it's harder than some beginner airplanes to fly, a three-year-old could land it.
And best of all, the out-of-pocket cost was only $3!
Roger Cost Rochester, New York
Transcribed from original scans by AI. Minor OCR errors may remain.
